
/***********************************************
	streamcluster_omp.cpp
	: parallelized code of streamcluster using OpenMP

	- original code from PARSEC Benchmark Suite
	- parallelization with OpenMP API has been applied by

	Sang-Ha (a.k.a Shawn) Lee - sl4ge@virginia.edu
	University of Virginia
	Department of Electrical and Computer Engineering
	Department of Computer Science

***********************************************/
//fastflow
#include <ff/parallel_for.hpp>
#include <ff/pipeline.hpp>
#include <ff/farm.hpp>
#include <ff/map.hpp>

#include <thread>         // std::this_thread::sleep_for
#include <chrono>         // std::chrono::second


#include <stdio.h>
#include <iostream>
#include <fstream>
#include <stdlib.h>
#include <sys/time.h>
#include <string.h>
#include <assert.h>
#include <math.h>
#include <sys/resource.h>
#include <limits.h>
#include <omp.h>

#ifdef ENABLE_PARSEC_HOOKS
#include <hooks.h>
#endif

using namespace std;
using namespace ff;

#define MAXNAMESIZE 1024 // max filename length
#define SEED 1
/* increase this to reduce probability of random error */
/* increasing it also ups running time of "speedy" part of the code */
/* SP = 1 seems to be fine */
#define SP 1 // number of repetitions of speedy must be >=1

/* higher ITER --> more likely to get correct # of centers */
/* higher ITER also scales the running time almost linearly */
#define ITER 3 // iterate ITER* k log k times; ITER >= 1

#define PRINTINFO //comment this out to disable output
#define PROFILE // comment this out to disable instrumentation code
//#define ENABLE_THREADS  // comment this out to disable threads
//#define INSERT_WASTE //uncomment this to insert waste computation into dist function

// fastflow parallefor parameters used in pgain() parallelization
#define FASTFLOW      //comment this out to enable fastflow parallel for in pgain function

int  FARM_WORKERS = 1; // number of workers in the farm
int  PFWORKERS = 1;   // parallel_for parallelism degree
int  PFGRAIN = 0;     // dafualt static scheduling of iterations

#define CACHE_LINE 512 // cache line in byte


static int nproc; //# of threads
static int c, d;  //c counts the number of pgain class, d count number of loops
//static int ompthreads;


// instrumentation code
#ifdef PROFILE
double time_local_search;
double time_speedy;
double time_select_feasible;
double time_gain;
double time_shuffle;
double time_gain_dist;
double time_gain_init;
#endif


//######################################################
//#####################   my points class ###############
//#######################################################

struct Point{
/*  Point(int dim) {
		for(int i=0; i < dim ; i++)
			coord.push_back(new long());
    }*/

  //~Point(){delete coord;}; ?? free(coord)

  float weight;
  float *coord; //coord points to an array of dim long

  long assign;  // number of point where this one is assigned
  float cost;  // cost of that assignment, weight*distance
  long ID;   //point ID: the position on the stream (dido).
};

// this is the array of points
struct Points {
  Points(int d, long n):num{n},dim{d}{
		 p = new Point[n];
  }

  ~Points(){delete []p;};

  long num; // number of points; may not be N if this is a sample
  int dim;  // dimensionality
  Point * p; // the array itself
//  std::vector<Point> p;
};


//prints the points
void printPoints( Points *points){

  for(int i = 0; i < points->num; ++i){
    std::cout << points->p[i].ID <<"\n";
    std::cout << points->p[i].weight <<"\n";
    for(int k=0; k< points->dim; ++k){
    std:cout << points->p[i].coord[k] <<" ";
    }
    std::cout<< "\n\n";
  }

}

/*
// this structure represents a point
// these will be passed around to avoid copying coordinates
typedef struct {
  float weight;
  float *coord;
  long assign;  // number of point where this one is assigned
  float cost;  // cost of that assignment, weight*distance
} Point;

// this is the array of points
typedef struct {
  long num; //number of points; may not be N if this is a sample
  int dim;  // dimensionality
  Point *p; //the array itself
} Points;

*/
double gettime() {
  struct timeval t;
  gettimeofday(&t,NULL);
  return (double)t.tv_sec+t.tv_usec*1e-6;
}


/* shuffle an array of integers */
void intshuffle(int *intarray, int length)
{
#ifdef PROFILE
  double t1 = gettime();
#endif
  long i, j;
  int temp;
  for (i=0;i<length;i++) {
    j=(lrand48()%(length - i))+i;
    temp = intarray[i];
    intarray[i]=intarray[j];
    intarray[j]=temp;
  }
#ifdef PROFILE
  double t2 = gettime();
  time_shuffle += t2-t1;
#endif
}
/* shuffle points into random order */
void shuffle(Points *points)
{
#ifdef PROFILE
  double t1 = gettime();
#endif
  long i, j;
  Point temp;
  for (i=0;i<points->num-1;i++) {
    j=(lrand48()%(points->num - i)) + i;
    temp = points->p[i];
    points->p[i] = points->p[j];
    points->p[j] = temp;
  }
#ifdef PROFILE
  double t2 = gettime();
  time_shuffle += t2-t1;
#endif
}

/* compute Euclidean distance squared between two points */
float dist(Point p1, Point p2, int dim)
{
  int i;
  float result=0.0;
  for (i=0;i<dim;i++)
    result += (p1.coord[i] - p2.coord[i])*(p1.coord[i] - p2.coord[i]);
#ifdef INSERT_WASTE
  double s = waste(result);
  result += s;
  result -= s;
#endif
  return(result);
}

struct pkmedian_arg_t
{
  Points* points;
  long kmin;
  long kmax;
  long* kfinal;
  int pid;
  pthread_barrier_t* barrier;
};



class PStream {
public:
  virtual size_t read( float* dest, int dim, int num ) = 0;
  virtual int ferror() = 0;
  virtual int feof() = 0;
  virtual ~PStream() {
  }
};

//synthetic stream
class SimStream : public PStream {
public:
  SimStream(long n_ ) {
    n = n_;
  }
  size_t read( float* dest, int dim, int num ) {
    size_t count = 0;
    for( int i = 0; i < num && n > 0; i++ ) {
      for( int k = 0; k < dim; k++ ) {
	dest[i*dim + k] = lrand48()/(float)INT_MAX;
      }
      n--;
      count++;
    }
    return count;
  }
  int ferror() {
    return 0;
  }
  int feof() {
    return n <= 0;
  }
  ~SimStream() {
  }
private:
  long n;
};

class FileStream : public PStream {
public:
  FileStream(char* filename) {
    fp = fopen( filename, "rb");
    if( fp == NULL ) {
      fprintf(stderr,"error opening file %s\n.",filename);
      exit(1);
    }
  }
  size_t read( float* dest, int dim, int num ) {
    return std::fread(dest, sizeof(float)*dim, num, fp);
  }
  int ferror() {
    return std::ferror(fp);
  }
  int feof() {
    return std::feof(fp);
  }
  ~FileStream() {
    printf("closing file stream\n");
    fclose(fp);
  }
private:
  FILE* fp;
};

void outcenterIDs( Points* centers, long* centerIDs, char* outfile ) {
  FILE* fp = fopen(outfile, "w");
  if( fp==NULL ) {
    fprintf(stderr, "error opening %s\n",outfile);
    exit(1);
  }
  int* is_a_median = (int*)calloc( sizeof(int), centers->num );
  for( int i =0 ; i< centers->num; i++ ) {
    is_a_median[centers->p[i].assign] = 1;
  }

  for( int i = 0; i < centers->num; i++ ) {
    if( is_a_median[i] ) {
      fprintf(fp, "%u\n", centerIDs[i]);
      fprintf(fp, "%lf\n", centers->p[i].weight);
      for( int k = 0; k < centers->dim; k++ ) {
	fprintf(fp, "%lf ", centers->p[i].coord[k]);
      }
      fprintf(fp,"\n\n");
    }
  }
  fclose(fp);
}

// Emitter
struct EmitterChunks:ff_node_t<Points>{

  EmitterChunks(PStream *Stream, long cksize, long d): stream(Stream), chunksize(cksize), dim(d){}

  Points *svc (Points *){  //generates the stream

  long IDoffset = 0;

  while(!stream->feof()){
      float* block = (float*)malloc(chunksize*dim*sizeof(float) );
      //float* centerBlock = (float*)malloc(centersize*dim*sizeof(float) );
      //long* centerIDs = (long*)malloc(centersize*dim*sizeof(long));

      if(block == NULL ) {
        	fprintf(stderr,"not enough memory for a chunk!\n");
          	exit(1);
      }

      Points *points = new Points(dim, chunksize);

      for( int i = 0; i < chunksize; i++ ) {
	         points->p[i].coord = &block[i*dim];  // points contains pointer to the block array containting the coordinates
      }

      size_t numRead  = stream->read(block, dim, chunksize);

      fprintf(stderr,"Emitter read %zu points\n", numRead);

      if( stream->ferror() || numRead < (unsigned int)chunksize && !stream->feof() ) {
        	fprintf(stderr, "error reading data!\n");
        	return(EOS);
      }

      points->num = numRead;
      for( int i = 0; i < points->num; i++ ) {
      	points->p[i].weight = 1.0;
      	points->p[i].ID = IDoffset + i;
      }

      IDoffset +=numRead;

      ff_send_out(points);
    }

    return EOS;   // the stream is finished
  }

  long chunksize;
  int dim;
  PStream *stream;
};


// Map worker

/* worker receive a chunk and produce k centers of the chunk received.*/
struct mapWorker:ff_Map<Points,Points,double>{

  int dim;
  long kmin;
  long kmax;
  long centersize;
  bool *switch_membership; //whether to switch membership in pgain
  bool* is_center; //whether a point is a center
  int* center_table; //index table of centers

  using map = ff_Map<Points,Points,double>; //double is the type of reduction variable

  mapWorker(int d, long kMIN, long kMAX, long centersz ):map(PFWORKERS), dim{d},kmin{kMIN},kmax{kMAX},centersize{centersz}{}

  Points * svc( Points * points){
		//const Points & points = *ps;

		float* centerBlock = (float*)malloc(centersize*dim*sizeof(float) );

		std::cout << "The worker n° " << get_my_id()<<" has received a chunk with " << points->num << " points " <<" \n";
    //std::this_thread::sleep_for (std::chrono::seconds(2));

		Points * centers = new Points(dim,centersize);
		centers->num = 0;
		for( int i = 0; i< centersize; i++ ) {
	    centers->p[i].coord = &centerBlock[i*dim];
	    centers->p[i].weight = 1.0;
	  }

		switch_membership = (bool*)malloc(points.num*sizeof(bool));
		is_center = (bool*)calloc(points.num,sizeof(bool));
		center_table = (int*)malloc(points.num*sizeof(int));

		long kfinal;
		localSearch(points, kmin, kmax, &kfinal);
		std::cout << "The worker n° " << get_my_id()<<" has found " << kfinal << " centers " <<" \n";

		delete ps;
    //ff_send_out(ps);
    return GO_ON;

  }


	/* For a given point x, find the cost of the following operation:
	 * -- open a facility at x if there isn't already one there,
	 * -- for points y such that the assignment distance of y exceeds dist(y, x),
	 *    make y a member of x,
	 * -- for facilities y such that reassigning y and all its members to x
	 *    would save cost, realize this closing and reassignment.
	 *
	 * If the cost of this operation is negative (i.e., if this entire operation
	 * saves cost), perform this operation and return the amount of cost saved;
	 * otherwise, do nothing.
	 */

	/* numcenters will be updated to reflect the new number of centers */
	/* z is the facility cost, x is the number of this point in the array
	   points */

	double pgain(long x, Points *points, double z, long int *numcenters, int pid, pthread_barrier_t* barrier)
	{
	  //  printf("pgain pthread %d begin\n",pid);
	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif
	#ifdef PROFILE
	  double t0 = gettime();
	#endif

	  //my block
	  long bsize = points->num/nproc;
	  long k1 = bsize * pid;
	  long k2 = k1 + bsize;
	  if( pid == nproc-1 ) k2 = points->num;

	  int i;
	  int number_of_centers_to_close = 0;

	  static double *work_mem;
	  static double gl_cost_of_opening_x;
	  static int gl_number_of_centers_to_close;

	  //each thread takes a block of working_mem.
	  int stride = *numcenters+2;
	  //make stride a multiple of CACHE_LINE
	  int cl = CACHE_LINE/sizeof(double);
	  if( stride % cl != 0 ) {
	    stride = cl * ( stride / cl + 1);
	  }
	  int K = stride -2 ; // K==*numcenters

	  //my own cost of opening x
	  double cost_of_opening_x = 0;

	  if( pid==0 )    {
	    work_mem = (double*) malloc(stride*(nproc+1)*sizeof(double));
	    gl_cost_of_opening_x = 0;
	    gl_number_of_centers_to_close = 0;
	  }

	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif
	  /*For each center, we have a *lower* field that indicates
	    how much we will save by closing the center.
	    Each thread has its own copy of the *lower* fields as an array.
	    We first build a table to index the positions of the *lower* fields.
	  */

	  int count = 0;
	  for( int i = k1; i < k2; i++ ) {
	    if( is_center[i] ) {
	      center_table[i] = count++;
	    }
	  }
	  work_mem[pid*stride] = count;

	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif

	  if( pid == 0 ) {
	    int accum = 0;
	    for( int p = 0; p < nproc; p++ ) {
	      int tmp = (int)work_mem[p*stride];
	      work_mem[p*stride] = accum;
	      accum += tmp;
	    }
	  }

	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif

	  for( int i = k1; i < k2; i++ ) {
	    if( is_center[i] ) {
	      center_table[i] += (int)work_mem[pid*stride];
	    }
	  }

	  //now we finish building the table. clear the working memory.
	  memset(switch_membership + k1, 0, (k2-k1)*sizeof(bool));
	  memset(work_mem+pid*stride, 0, stride*sizeof(double));
	  if( pid== 0 ) memset(work_mem+nproc*stride,0,stride*sizeof(double));

	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif
	#ifdef PROFILE
	  double t1 = gettime();
	  if( pid == 0 ) time_gain_init += t1-t0;
	#endif
	  //my *lower* fields
	  double* lower = &work_mem[pid*stride];
	  //global *lower* fields
	  double* gl_lower = &work_mem[nproc*stride];

	  for ( i = k1; i < k2; i++ ) {
	    float x_cost = dist(points->p[i], points->p[x], points->dim)
	      * points->p[i].weight;
	    float current_cost = points->p[i].cost;

	    if ( x_cost < current_cost ) {

	      // point i would save cost just by switching to x
	      // (note that i cannot be a median,
	      // or else dist(p[i], p[x]) would be 0)

	      switch_membership[i] = 1;
	      cost_of_opening_x += x_cost - current_cost;

	    } else {

	      // cost of assigning i to x is at least current assignment cost of i

	      // consider the savings that i's **current** median would realize
	      // if we reassigned that median and all its members to x;
	      // note we've already accounted for the fact that the median
	      // would save z by closing; now we have to subtract from the savings
	      // the extra cost of reassigning that median and its members
	      int assign = points->p[i].assign;
	      lower[center_table[assign]] += current_cost - x_cost;
	    }
	  }

	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif

	#ifdef PROFILE
	  double t2 = gettime();
	  if( pid==0){
	    time_gain_dist += t2 - t1;
	  }
	#endif

	  // at this time, we can calculate the cost of opening a center
	  // at x; if it is negative, we'll go through with opening it

	  for ( int i = k1; i < k2; i++ ) {
	    if( is_center[i] ) {
	      double low = z;
	      //aggregate from all threads
	      for( int p = 0; p < nproc; p++ ) {
		low += work_mem[center_table[i]+p*stride];
	      }
	      gl_lower[center_table[i]] = low;
	      if ( low > 0 ) {
		// i is a median, and
		// if we were to open x (which we still may not) we'd close i

		// note, we'll ignore the following quantity unless we do open x
		++number_of_centers_to_close;
		cost_of_opening_x -= low;
	      }
	    }
	  }
	  //use the rest of working memory to store the following
	  work_mem[pid*stride + K] = number_of_centers_to_close;
	  work_mem[pid*stride + K+1] = cost_of_opening_x;

	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif
	  //  printf("thread %d cost complete\n",pid);

	  if( pid==0 ) {
	    gl_cost_of_opening_x = z;
	    //aggregate
	    for( int p = 0; p < nproc; p++ ) {
	      gl_number_of_centers_to_close += (int)work_mem[p*stride + K];
	      gl_cost_of_opening_x += work_mem[p*stride+K+1];
	    }
	  }
	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif
	  // Now, check whether opening x would save cost; if so, do it, and
	  // otherwise do nothing

	  if ( gl_cost_of_opening_x < 0 ) {
	    //  we'd save money by opening x; we'll do it
	    for ( int i = k1; i < k2; i++ ) {
	      bool close_center = gl_lower[center_table[points->p[i].assign]] > 0 ;
	      if ( switch_membership[i] || close_center ) {
		// Either i's median (which may be i itself) is closing,
		// or i is closer to x than to its current median
		points->p[i].cost = points->p[i].weight *
		  dist(points->p[i], points->p[x], points->dim);
		points->p[i].assign = x;
	      }
	    }
	    for( int i = k1; i < k2; i++ ) {
	      if( is_center[i] && gl_lower[center_table[i]] > 0 ) {
		is_center[i] = false;
	      }
	    }
	    if( x >= k1 && x < k2 ) {
	      is_center[x] = true;
	    }
	    //    pthread_barrier_wait(barrier);

	    if( pid==0 ) {
	      *numcenters = *numcenters + 1 - gl_number_of_centers_to_close;
	    }
	  }
	  else {
	    if( pid==0 )
	      gl_cost_of_opening_x = 0;  // the value we'll return
	  }
	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif
	  if( pid == 0 ) {
	    free(work_mem);
	    //    free(is_center);
	    //    free(switch_membership);
	    //    free(proc_cost_of_opening_x);
	    //    free(proc_number_of_centers_to_close);
	  }

	#ifdef PROFILE
	  double t3 = gettime();
	  if( pid==0 )
	  time_gain += t3-t0;
	#endif
	  return -gl_cost_of_opening_x;
	}


	/* run speedy on the points, return total cost of solution */
	float pspeedy(Points *points, float z, long *kcenter, int pid, pthread_barrier_t* barrier)
	{
	#ifdef PROFILE
	  double t1 = gettime();
	#endif

	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif
	  //my block
	  long bsize = points->num/nproc;
	  long k1 = bsize * pid;
	  long k2 = k1 + bsize;
	  if( pid == nproc-1 ) k2 = points->num;

	  static double totalcost;

	  static bool open = false;
	  static double* costs; //cost for each thread.
	  static int i;

	#ifdef ENABLE_THREADS
	  static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
	  static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
	#endif

	#ifdef PRINTINFO
	  if( pid == 0 ){
	    fprintf(stderr, "Speedy: facility cost %lf\n", z);
	  }
	#endif

	  /* create center at first point, send it to itself */
	  for( int k = k1; k < k2; k++ )    {
	    float distance = dist(points->p[k],points->p[0],points->dim);
	    points->p[k].cost = distance * points->p[k].weight;
	    points->p[k].assign=0;
	  }

	  if( pid==0 )   {
	    *kcenter = 1;
	    costs = (double*)malloc(sizeof(double)*nproc);
	  }

	  if( pid != 0 ) { // we are not the master threads. we wait until a center is opened.
	    while(1) {
	#ifdef ENABLE_THREADS
	      pthread_mutex_lock(&mutex);
	      while(!open) pthread_cond_wait(&cond,&mutex);
	      pthread_mutex_unlock(&mutex);
	#endif
	      if( i >= points->num ) break;
	      for( int k = k1; k < k2; k++ )
		{
		  float distance = dist(points->p[i],points->p[k],points->dim);
		  if( distance*points->p[k].weight < points->p[k].cost )
		    {
		      points->p[k].cost = distance * points->p[k].weight;
		      points->p[k].assign=i;
		    }
		}
	#ifdef ENABLE_THREADS
	      pthread_barrier_wait(barrier);
	      pthread_barrier_wait(barrier);
	#endif
	    }
	  }
	  else  { // I am the master thread. I decide whether to open a center and notify others if so.
	    for(i = 1; i < points->num; i++ )  {
	      bool to_open = ((float)lrand48()/(float)INT_MAX)<(points->p[i].cost/z);
	      if( to_open )  {
		(*kcenter)++;
	#ifdef ENABLE_THREADS
		pthread_mutex_lock(&mutex);
	#endif
		open = true;
	#ifdef ENABLE_THREADS
		pthread_mutex_unlock(&mutex);
		pthread_cond_broadcast(&cond);
	#endif
		for( int k = k1; k < k2; k++ )  {
		  float distance = dist(points->p[i],points->p[k],points->dim);
		  if( distance*points->p[k].weight < points->p[k].cost )  {
		    points->p[k].cost = distance * points->p[k].weight;
		    points->p[k].assign=i;
		  }
		}
	#ifdef ENABLE_THREADS
		pthread_barrier_wait(barrier);
	#endif
		open = false;
	#ifdef ENABLE_THREADS
		pthread_barrier_wait(barrier);
	#endif
	      }
	    }
	#ifdef ENABLE_THREADS
	    pthread_mutex_lock(&mutex);
	#endif
	    open = true;
	#ifdef ENABLE_THREADS
	    pthread_mutex_unlock(&mutex);
	    pthread_cond_broadcast(&cond);
	#endif
	  }
	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif
	  open = false;
	  double mytotal = 0;
	  for( int k = k1; k < k2; k++ )  {
	    mytotal += points->p[k].cost;
	  }
	  costs[pid] = mytotal;
	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif
	  // aggregate costs from each thread
	  if( pid == 0 )
	    {
	      totalcost=z*(*kcenter);
	      for( int i = 0; i < nproc; i++ )
		{
		  totalcost += costs[i];
		}
	      free(costs);
	    }
	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif

	#ifdef PRINTINFO
	  if( pid == 0 )
	    {
	      fprintf(stderr, "Speedy opened %d facilities for total cost %lf\n",
		      *kcenter, totalcost);
	      fprintf(stderr, "Distance Cost %lf\n", totalcost - z*(*kcenter));
	    }
	#endif

	#ifdef PROFILE
	  double t2 = gettime();
	  if( pid== 0 ) {
	    time_speedy += t2 -t1;
	  }
	#endif
	  return(totalcost);
	}


	/* facility location on the points using local search */
	/* z is the facility cost, returns the total cost and # of centers */
	/* assumes we are seeded with a reasonable solution */
	/* cost should represent this solution's cost */
	/* halt if there is < e improvement after iter calls to gain */
	/* feasible is an array of numfeasible points which may be centers */

	float pFL(Points *points, int *feasible, int numfeasible,
		  float z, long *k, double cost, long iter, float e,
		  int pid, pthread_barrier_t* barrier)
	{
	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif
	  long i;
	  long x;
	  double change;
	  long numberOfPoints;

	  change = cost;
	  /* continue until we run iter iterations without improvement */
	  /* stop instead if improvement is less than e */
	  while (change/cost > 1.0*e) {
	    change = 0.0;
	    numberOfPoints = points->num;
	    /* randomize order in which centers are considered */

	    if( pid == 0 ) {
	      intshuffle(feasible, numfeasible);
	    }
	#ifdef ENABLE_THREADS
	    pthread_barrier_wait(barrier);
	#endif
	    for (i=0;i<iter;i++) {
	      x = i%numfeasible;
	      change += pgain(feasible[x], points, z, k, pid, barrier);
	    }

	    cost -= change;
	#ifdef PRINTINFO
	    if( pid == 0 ) {
	      fprintf(stderr, "%d centers, cost %lf, total distance %lf\n",
		      *k, cost, cost - z*(*k));
	    }
	#endif
	#ifdef ENABLE_THREADS
	    pthread_barrier_wait(barrier);
	#endif
	  }
	  return(cost);
	}


	int selectfeasible_fast(Points *points, int **feasible, int kmin, int pid, pthread_barrier_t* barrier)
	{
	#ifdef PROFILE
	  double t1 = gettime();
	#endif

	  int numfeasible = points->num;
	  if (numfeasible > (ITER*kmin*log((double)kmin)))
	    numfeasible = (int)(ITER*kmin*log((double)kmin));
	  *feasible = (int *)malloc(numfeasible*sizeof(int));

	  float* accumweight;
	  float totalweight;

	  /*
	     Calcuate my block.
	     For now this routine does not seem to be the bottleneck, so it is not parallelized.
	     When necessary, this can be parallelized by setting k1 and k2 to
	     proper values and calling this routine from all threads ( it is called only
	     by thread 0 for now ).
	     Note that when parallelized, the randomization might not be the same and it might
	     not be difficult to measure the parallel speed-up for the whole program.
	   */
	  //  long bsize = numfeasible;
	  long k1 = 0;
	  long k2 = numfeasible;

	  float w;
	  int l,r,k;

	  /* not many points, all will be feasible */
	  if (numfeasible == points->num) {
	    for (int i=k1;i<k2;i++)
	      (*feasible)[i] = i;
	    return numfeasible;
	  }

	  accumweight= (float*)malloc(sizeof(float)*points->num);
	  accumweight[0] = points->p[0].weight;
	  totalweight=0;
	  for( int i = 1; i < points->num; i++ ) {
	    accumweight[i] = accumweight[i-1] + points->p[i].weight;
	  }
	  totalweight=accumweight[points->num-1];

	  for(int i=k1; i<k2; i++ ) {
	    w = (lrand48()/(float)INT_MAX)*totalweight;
	    //binary search
	    l=0;
	    r=points->num-1;
	    if( accumweight[0] > w )  {
	      (*feasible)[i]=0;
	      continue;
	    }
	    while( l+1 < r ) {
	      k = (l+r)/2;
	      if( accumweight[k] > w ) {
		r = k;
	      }
	      else {
		l=k;
	      }
	    }
	    (*feasible)[i]=r;
	  }

	  free(accumweight);

	#ifdef PROFILE
	  double t2 = gettime();
	  time_select_feasible += t2-t1;
	#endif
	  return numfeasible;
	}


	/* compute approximate kmedian on the points */
	float pkmedian(Points *points, long kmin, long kmax, long* kfinal,
		       int pid, pthread_barrier_t* barrier )
	{
	  int i;
	  double cost;
	  double lastcost;
	  double hiz, loz, z;

	  static long k;
	  static int *feasible;
	  static int numfeasible;
	  static double* hizs;

	  if( pid==0 ) hizs = (double*)calloc(nproc,sizeof(double));
	  hiz = loz = 0.0;
	  long numberOfPoints = points->num;
	  long ptDimension = points->dim;

	  //my block
	  long bsize = points->num/nproc;
	  long k1 = bsize * pid;
	  long k2 = k1 + bsize;
	  if( pid == nproc-1 ) k2 = points->num;

	#ifdef PRINTINFO
	  if( pid == 0 )
	    {
	      printf("Starting Kmedian procedure\n");
	      printf("%i points in %i dimensions\n", numberOfPoints, ptDimension);
	    }
	#endif

	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif

	  double myhiz = 0;
	  for (long kk=k1;kk < k2; kk++ ) {
	    myhiz += dist(points->p[kk], points->p[0],
			      ptDimension)*points->p[kk].weight;
	  }
	  hizs[pid] = myhiz;

	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif

	  for( int i = 0; i < nproc; i++ )   {
	    hiz += hizs[i];
	  }

	  loz=0.0; z = (hiz+loz)/2.0;
	  /* NEW: Check whether more centers than points! */
	  if (points->num <= kmax) {
	    /* just return all points as facilities */
	    for (long kk=k1;kk<k2;kk++) {
	      points->p[kk].assign = kk;
	      points->p[kk].cost = 0;
	    }
	    cost = 0;
	    if( pid== 0 ) {
	      free(hizs);
	      *kfinal = k;
	    }
	    return cost;
	  }

	  if( pid == 0 ) shuffle(points);
	  cost = pspeedy(points, z, &k, pid, barrier);

	#ifdef PRINTINFO
	  if( pid == 0 )
	    printf("thread %d: Finished first call to speedy, cost=%lf, k=%i\n",pid,cost,k);
	#endif
	  i=0;
	  /* give speedy SP chances to get at least kmin/2 facilities */
	  while ((k < kmin)&&(i<SP)) {
	    cost = pspeedy(points, z, &k, pid, barrier);
	    i++;
	  }

	#ifdef PRINTINFO
	  if( pid==0)
	    printf("thread %d: second call to speedy, cost=%lf, k=%d\n",pid,cost,k);
	#endif
	  /* if still not enough facilities, assume z is too high */
	  while (k < kmin) {
	#ifdef PRINTINFO
	    if( pid == 0 ) {
	      printf("%lf %lf\n", loz, hiz);
	      printf("Speedy indicates we should try lower z\n");
	    }
	#endif
	    if (i >= SP) {hiz=z; z=(hiz+loz)/2.0; i=0;}
	    if( pid == 0 ) shuffle(points);
	    cost = pspeedy(points, z, &k, pid, barrier);
	    i++;
	  }

	  /* now we begin the binary search for real */
	  /* must designate some points as feasible centers */
	  /* this creates more consistancy between FL runs */
	  /* helps to guarantee correct # of centers at the end */

	  if( pid == 0 )
	    {
	      numfeasible = selectfeasible_fast(points,&feasible,kmin,pid,barrier);
	      for( int i = 0; i< points->num; i++ ) {
		is_center[points->p[i].assign]= true;
	      }
	    }

	#ifdef ENABLE_THREADS
	  pthread_barrier_wait(barrier);
	#endif

	  while(1) {
	#ifdef PRINTINFO
	    if( pid==0 )
	      {
		printf("loz = %lf, hiz = %lf\n", loz, hiz);
		printf("Running Local Search...\n");
	      }
	#endif
	    /* first get a rough estimate on the FL solution */
	    //    pthread_barrier_wait(barrier);

	    lastcost = cost;
	    cost = pFL(points, feasible, numfeasible,
		       z, &k, cost, (long)(ITER*kmax*log((double)kmax)), 0.1, pid, barrier);

	    /* if number of centers seems good, try a more accurate FL */
	    if (((k <= (1.1)*kmax)&&(k >= (0.9)*kmin))||
		((k <= kmax+2)&&(k >= kmin-2))) {

	#ifdef PRINTINFO
	      if( pid== 0)
		{
		  printf("Trying a more accurate local search...\n");
		}
	#endif
	      /* may need to run a little longer here before halting without
		 improvement */
	      cost = pFL(points, feasible, numfeasible,
			 z, &k, cost, (long)(ITER*kmax*log((double)kmax)), 0.001, pid, barrier);
	    }

	    if (k > kmax) {
	      /* facilities too cheap */
	      /* increase facility cost and up the cost accordingly */
	      loz = z; z = (hiz+loz)/2.0;
	      cost += (z-loz)*k;
	    }
	    if (k < kmin) {
	      /* facilities too expensive */
	      /* decrease facility cost and reduce the cost accordingly */
	      hiz = z; z = (hiz+loz)/2.0;
	      cost += (z-hiz)*k;
	    }

	    /* if k is good, return the result */
	    /* if we're stuck, just give up and return what we have */
	    if (((k <= kmax)&&(k >= kmin))||((loz >= (0.999)*hiz)) )
	      {
		break;
	      }
	#ifdef ENABLE_THREADS
	    pthread_barrier_wait(barrier);
	#endif
	  }

	  //clean up...
	  if( pid==0 ) {
	    free(feasible);
	    free(hizs);
	    *kfinal = k;
	  }

	  return cost;
	}

	void* localSearchSub(void* arg_) {

	  pkmedian_arg_t* arg= (pkmedian_arg_t*)arg_;
	  pkmedian(arg->points,arg->kmin,arg->kmax,arg->kfinal,arg->pid,arg->barrier);

	  return NULL;
	}


	void localSearch( Points* points, long kmin, long kmax, long* kfinal ) {
	#ifdef PROFILE
	  double t1 = gettime();
	#endif

	    pthread_barrier_t barrier;
	#ifdef ENABLE_THREADS
	    pthread_barrier_init(&barrier,NULL,nproc);
	#endif
	    pthread_t* threads = new pthread_t[nproc];
	    pkmedian_arg_t* arg = new pkmedian_arg_t[nproc];


	    for( int i = 0; i < nproc; i++ ) {
	      arg[i].points = points;
	      arg[i].kmin = kmin;
	      arg[i].kmax = kmax;
	      arg[i].pid = i;
	      arg[i].kfinal = kfinal;

	      arg[i].barrier = &barrier;
	#ifdef ENABLE_THREADS
	      pthread_create(threads+i,NULL,localSearchSub,(void*)&arg[i]);
	#else
	      localSearchSub(&arg[0]);
	#endif
	    }

	    for ( int i = 0; i < nproc; i++) {
	#ifdef ENABLE_THREADS
	      pthread_join(threads[i],NULL);
	#endif
	    }

	    delete[] threads;
	    delete[] arg;
	#ifdef ENABLE_THREADS
	    pthread_barrier_destroy(&barrier);
	#endif

	#ifdef PROFILE
	  double t2 = gettime();
	  time_local_search += t2-t1;
	#endif

	}

}; //end worker definition




// collector
struct lastStage:ff_minode_t<Points> { // NOTE multi-input node
  int dim;
  long kmin,kmax,clustersize;
  char * outfile;
  long counter;
  Points *cluster_centers; //vector of centers from workers
  bool* switch_membership;
  bool* is_center;
  int *center_table;


  lastStage(int d, long kMIN, long kMAX, char* out, long clustersz):dim(d),kmin(kMIN), kmax(kMAX), clustersize(clustersz), outfile(out){}



  Points* svc(Points * centers){

    std::cout << "The Collector " << get_my_id()<<" has received "<<centers->num<<" centers  points \n";

  }




}; //end collector


int main(int argc, char **argv)
{
  char *outfilename = new char[MAXNAMESIZE];
  char *infilename = new char[MAXNAMESIZE];
  long kmin, kmax, n, chunksize, clustersize;
  int dim;
  /*      int numthreads;/*/
  c = 0;
  d = 0;


  if (argc<11) {
    fprintf(stderr,"usage: %s k1 k2 d n chunksize clustersize infile outfile farmWorkers mapWorkers \n",
	    argv[0]);
    fprintf(stderr,"  k1:          Min. number of centers allowed\n");
    fprintf(stderr,"  k2:          Max. number of centers allowed\n");
    fprintf(stderr,"  d:           Dimension of each data point\n");
    fprintf(stderr,"  n:           Number of data points\n");
    fprintf(stderr,"  chunksize:   Number of data points to handle per step\n");
    fprintf(stderr,"  clustersize: Maximum number of intermediate centers\n");
    fprintf(stderr,"  infile:      Input file (if n<=0)\n");
    fprintf(stderr,"  outfile:     Output file\n");
    fprintf(stderr,"  farmWorkers: Number of workers to use in the farm\n");
    fprintf(stderr,"  pfWorkers:   Number of workers to use in the parallel for\n");
    fprintf(stderr,"\n");
    fprintf(stderr, "if n > 0, points will be randomly generated instead of reading from infile.\n");
    exit(1);
  }
  kmin = atoi(argv[1]);
  kmax = atoi(argv[2]);
  dim = atoi(argv[3]);
  n = atoi(argv[4]);
  chunksize = atoi(argv[5]);
  clustersize = atoi(argv[6]);
  strcpy(infilename, argv[7]);
  strcpy(outfilename, argv[8]);
  nproc = atoi(argv[9]);

#ifdef FASTFLOW
  PFWORKERS =  atoi(argv[10]);
  FARM_WORKERS = nproc;
  PFGRAIN = 0;
  nproc = 1;
#endif

  srand48(SEED);
  PStream* stream;
  if( n > 0 ) {
    stream = new SimStream(n);
  }
  else {
    stream = new FileStream(infilename);
  }

  // Fastflow emitter produces the stream of chuncksize elements.
  EmitterChunks emitter(stream, chunksize, dim);

  // Fastflow workers finds the  medians in the stream received.
  std::vector<std::unique_ptr<ff_node>> Workers;

  for( int i=0; i<FARM_WORKERS; ++i){
    Workers.push_back(make_unique<mapWorker>(dim, kmin, kmax, clustersize));  //(int d, long kMIN, long kMAX, long centersz )
  }

  // Fastflow Farm declaration
  ff_Farm<Points> myFarm (std::move(Workers),emitter);
  myFarm.remove_collector(); // remove the default collector

  //Collector
  lastStage Collector(dim,kmin,kmax,outfilename,clustersize);//long kMIN, long kMAX, char* out, long clustersz);

  //Pipe of farm and my collector
  ff_Pipe<Points> myPipe(myFarm, Collector);

  double t1 = gettime();
  if (myPipe.run_and_wait_end()<0) {
        error("running Pipe\n");
        return -1;
  }
  double t2 = gettime();

  printf("time = %lf\n",t2-t1);

  delete stream;

  printf("time pgain = %lf\n", time_gain);
  printf("time pgain_dist = %lf\n", time_gain_dist);
  printf("time pgain_init = %lf\n", time_gain_init);
  printf("time pselect = %lf\n", time_select_feasible);
  printf("time pspeedy = %lf\n", time_speedy);
  printf("time pshuffle = %lf\n", time_shuffle);
  printf("time localSearch = %lf\n", time_local_search);
  printf("loops=%d\n", d);


  return 0;
}
